Vibratory Mass Patents (Class 73/504.04)
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Patent number: 7059188Abstract: A flexible substrate (110) having flexibility and a fixed substrate (120) disposed so as to oppose it are supported at their peripheral portions by a sensor casing (140). An oscillator (130) is fixed on the lower surface of the flexible substrate. Five lower electrode layers (F1 to F5: F1 and F2 are disposed at front and back of F5) are formed on the upper surface of the flexible substrate. Five upper electrode layers (E1 to E5) are formed on the lower surface of the fixed substrate so as to oppose the lower electrodes. In the case of detecting an angular velocity ?x about the X-axis, an a.c. voltage is applied across a predetermined pair of opposite electrode layers (E5, F5) to allow the oscillator to undergo oscillation Uz in the Z-axis direction. Thus, a Coriolis force Fy proportional to the angular velocity ?x is applied to the oscillator in the Y-axis. By this Coriolis force Fy, the oscillator is caused to undergo displacement in the Y-axis direction.Type: GrantFiled: May 23, 2005Date of Patent: June 13, 2006Inventor: Kazuhiro Okada
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Patent number: 7057173Abstract: A measurement technique for normalizing the sensitive-axis output of a magnetoresistive (MR) sensor which greatly reduces both temperature effects and magnetic contributions from the insensitive-axis cross-terms. Specifically, the normalization techniques disclosed may be effectuated by direct measurement with no prior knowledge of the sensor constants being required and may be performed for a single sensor with multiple sensors not being required in order to estimate the cross-axis fields for each of the other sensors. The technique can additionally provide an output proportional to the insensitive-axis field as well as that of the sensitive-axis and, when combined with knowledge of ambient field strengths, can be used to determine fundamental MR sensor constants which then allows for correction of higher-order sensor non-linearities. The techniques disclosed are particularly conducive to low power supply availability applications such as battery operation.Type: GrantFiled: January 5, 2004Date of Patent: June 6, 2006Assignees: Laser Technology, Inc., Kama-Tech (HK) LimitedInventor: Layne L. Wright
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Patent number: 7051590Abstract: A movable microstructure includes a first finger set comprising two or more first fingers affixed to a substrate and extending substantially parallel to a defined displacement axis towards a proof-mass. The movable microstructure further includes a second finger set comprising at least one second finger, each member of the second finger set extending substantially parallel to the displacement axis from the proof-mass, terminating between two first fingers. Each second finger is substantially closer to one of the two first fingers between which it terminates. The first finger set, in conjunction with the second finger set, form two terminals of a capacitor. An electrical circuit is included that provides a voltage across the capacitor to generate a position-dependent force, the position-dependent force having a component along an axis substantially orthogonal to the displacement axis, the magnitude of the position-dependent force varying in proportion to displacement along the displacement axis.Type: GrantFiled: June 13, 2000Date of Patent: May 30, 2006Assignee: Analog Devices IMI, Inc.Inventors: Mark A. Lemkin, William A. Clark, Thor N. Juneau, Allen W. Roessig
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Patent number: 7043985Abstract: A microstructure comprising an in-plane solid-mass electrically conductive tuning fork gyroscope and fabrication methods. The gyroscope is formed using substrate material having lower and upper layers sandwiching a sacrificial insulating layer. An exemplary gyroscope comprises a low-resistivity single-crystal silicon substrate having a lower support layer and an upper flexible support layer. Two opposed proof masses that are separated from the lower support layer lie in and are supported by the upper flexible support layer. Two drive electrodes are disposed adjacent to the proof masses and are insulatably supported by the lower support layer and are separated from the upper flexible support layer. Sense, balance and tuning electrodes are disposed adjacent to the proof masses and are insulatably supported by the lower support layer and are separated from the upper flexible support layer.Type: GrantFiled: January 12, 2005Date of Patent: May 16, 2006Assignee: Georgia Tech Research CorporationInventors: Farrokh Ayazi, Mohammad Faisal Zaman
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Patent number: 6990864Abstract: A semiconductor dynamic quantity sensor includes a semiconductor substrate that includes a movable electrode, a pair of first fixed electrodes, and a pair of second fixed electrodes. The first and second pairs of first detection capacitances and the first and second pairs of second detection capacitances are formed by the electrodes. The dynamic quantity related to the force applied to the sensor is measured on the basis of the sum of the differential output between the first pair of the first detection capacitances, the differential output between the second pair of the first detection capacitances, the differential output between the first pair of the second detection capacitances, and the differential output between the second pair of the second detection capacitances, when the movable electrode moves along the first direction or the second direction under the force. The sum includes a relatively small amount of noises.Type: GrantFiled: November 19, 2002Date of Patent: January 31, 2006Assignee: Denso CorporationInventor: Minekazu Sakai
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Patent number: 6981414Abstract: A suspended, coupled micromachined structure including two proof masses and multiple support arms configured to suspend the masses above a substrate and a coupling spring element having two ends. Each end of the coupling spring element may be attached to a proof mass at a point between the proof masses. The frequency response characteristics of the proof masses may be improved.Type: GrantFiled: April 1, 2004Date of Patent: January 3, 2006Assignee: Honeywell International Inc.Inventors: Gary R. Knowles, Mark W. Weber
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Patent number: 6966224Abstract: Micromachined vibratory gyroscope having two or more coplanar movable masses suspended over a planar substrate. Two perpendicular axes (x and y) are defined within the substrate plane, while a third, the z-axis or input axis, is defined to be perpendicular to the substrate plane. The movements of the two masses along the x-axis are coupled through an electrostatic coupling means so that the natural resonant frequency of the in-phase mode and that of the anti-phase mode are separated from each other for the resonances along the x-axis. When the two masses are driven to vibrate along the x-axis in the anti-phase mode and the device experiences rotation about the z-axis, Coriolis forces act differentially on the masses in the Y-direction, causing the two masses to dither in an anti-phase motion along the y-axis. The anti-phase dithering along the y-axis can be sensed directly by a rate sensor to measure the rate of rotation about the z-axis.Type: GrantFiled: March 2, 2004Date of Patent: November 22, 2005Assignees: BEI Technologies, Inc., Conti Temic Microelectronic GmgH, Continental Teves AG & Co. oHGInventors: Hai Yan, Roland Burghardt, Bernhard Hartmann, Konrad Kapser, Matthias Rose
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Patent number: 6938483Abstract: This invention is related to a phase-locked mechanical resonator pair that comprises at least two mechanical resonators wherein the resonance of the second mechanical resonator is phase-locked to the resonance of the first mechanical, and a micromachined vibration gyroscope that uses such phase-locked mechanical resonator pair as its resonating masses to generate differential Coriolis forces and to achieve inertial cancellation.Type: GrantFiled: March 28, 2004Date of Patent: September 6, 2005Inventor: Hai Yan
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Patent number: 6934665Abstract: A method for extracting components from signals in an electronic sensor (50) having a sensing element (52). The sensing element (52) generates a first signal (60) and a second signal (62). The method comprises the steps of: receiving the first signal (60) from the sensing element (52), the first signal (60) having a frequency at an event; sampling the second signal (62) from the sensing element (52) based on the frequency of the event, the second signal (62) having a plurality of components, one of the plurality of components being a first component of interest (112, 114); generating a synchronized second signal (100) in a time domain, the second signal (62) having the plurality of components; generating complex data (110) in a frequency domain from the synchronized second signal (100) in the time domain; determining the first component of interest (112, 114) from the complex data (110); and normalizing the first component of interest (112, 114) using amplitude information from the first signal (60).Type: GrantFiled: October 22, 2003Date of Patent: August 23, 2005Assignee: Motorola, Inc.Inventor: Stephen J. Rober
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Patent number: 6928873Abstract: A silicon dual inertial sensor made of a (110) silicon chip comprises at least a proof-mass, which is connected to a corresponding inner frame with a plurality of sensing resilient beams to make it easier for the proof-mass to move perpendicular to the surface of the silicon chip (defined as z-axis), and each inner frame is connected to an outer frame with a plurality of driving resilient beams, or connected to common connection beams, which are then connected to a central anchor with common resilient supporting beams to make it easier for the inner frame to move in parallel with the surface of the silicon chip (defined as y-axis). Each inner frame is driven by a driver to move in an opposite direction along the y-axis, and also move the proof-mass in the opposite direction along the y-axis. If there is a rotation rate input along the x-axis, it will generate a Coriolis force to make each proof-mass move in the opposite direction of the z-axis.Type: GrantFiled: November 1, 2003Date of Patent: August 16, 2005Assignee: Chung-Shan Institute Of Science And TechnologyInventors: Shyu-Mou Chen, Sheau-Shi Tzuoo, Chung-Ta Kau
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Patent number: 6928872Abstract: An integrated gyroscope, including an acceleration sensor formed by: a driving assembly; a sensitive mass extending in at least one first and second directions and being moved by the driving assembly in the first direction; and by a capacitive sensing electrode, facing the sensitive mass. The acceleration sensor has an rotation axis parallel to the second direction, and the sensitive mass is sensitive to forces acting in a third direction perpendicular to the other directions. The capacitive sensing electrode is formed by a conductive material region extending underneath the sensitive mass and spaced therefrom by an air gap.Type: GrantFiled: May 21, 2003Date of Patent: August 16, 2005Assignee: STMicroelectronics S.r.l.Inventors: Guido Spinola Durante, Sarah Zerbini, Angelo Merassi
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Patent number: 6907782Abstract: A micromechanical inertial sensor that includes three component planes, namely a bottom part, a center part and a cover part. The center part is a silicon wafer in which a cardan-type (i.e. gimbal) structure with two oscillating elements is formed. A plate is formed in the silicon wafer which can be pivoted about a rotational axis lying in the wafer plane. Metallized portions or conductive layers form an exciter unit and set the gimbal structure oscillating. The inventive sensor further comprises a device for detecting the displacement of the plate. In addition, a method for manufacturing a micromechanical inertial sensor.Type: GrantFiled: November 30, 2001Date of Patent: June 21, 2005Assignee: EADS Deutschland GmbHInventors: Konrad Lentner, Stefan Sassen, Josef Schalk
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Patent number: 6906849Abstract: A micro-mirror element includes a micro-mirror substrate, a wiring substrate and an electroconductive spacer disposed between the two substrates. The micro-mirror substrate is formed integral with a frame, a moving portion having a mirror portion, and a torsion bar connecting the frame to the moving portion. The wiring substrate is provided with a wiring pattern. The electroconductive spacer separates the micro-mirror substrate from the wiring substrate and also electrically connects the frame to the wiring pattern. The wiring substrate has a surface that faces the micro-mirror substrate. A detector is provided on this surface for detecting the pivot angle of the mirror portion.Type: GrantFiled: September 23, 2004Date of Patent: June 14, 2005Assignee: Fujitsu LimitedInventors: Xiaoyu Mi, Hiromitsu Soneda, Satoshi Ueda, Ippei Sawaki
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Patent number: 6894576Abstract: A time base including a resonator (4) and an integrated electronic circuit (3) for driving the resonator into oscillation and for producing, in response to the oscillation, a signal having a determined frequency. The resonator is an integrated micromechanical ring resonator supported above a substrate (2) and adapted to oscillate around an axis of rotation (O) substantially perpendicular to the substrate. The ring resonator includes a free-standing oscillating structure having a plurality of thermally compensating members (65) which are adapted to alter a mass moment of inertia of the free-standing oscillating structure as a function of temperature so as to compensate for the effect of temperature on the resonant frequency of the ring resonator.Type: GrantFiled: August 29, 2003Date of Patent: May 17, 2005Assignee: ETA SA Fabriques d'EbauchesInventors: Metin Giousouf, Heinz Kück, Rainer Platz
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Patent number: 6889550Abstract: The invention concerns a mechanical resonator with a planar monolithic vibrating structure extending along a closed contour whereof the axis of sensitivity is substantially perpendicular to the plane of said structure. The invention is characterised in that the planar structure (1) is a regular convex polygon with 4k vertices (3) (k being the order of the vibrational mode implemented when the resonator is vibrated) and is suspended to a fixed base (4, 5) via n suspension arms (2) with substantially radial extension arranged substantially symmetrically.Type: GrantFiled: January 29, 2002Date of Patent: May 10, 2005Assignee: SAGEM SAInventor: José Beitia
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Patent number: 6859113Abstract: A time base including a resonator (4) and an integrated electronic circuit (3) for driving the resonator into oscillation and for producing, in response to the oscillation, a signal having a determined frequency. The resonator is an integrated micromechanical ring resonator supported above a substrate (2) and adapted to oscillate in a first oscillation mode. The ring resonator includes a free-standing oscillating structure (6). Electrodes (100, 120; 130, 150) are positioned under the free-standing oscillating structure in such a way as to drive and sense a second oscillation mode in a plane substantially perpendicular to the substrate and having a resonant frequency which is different from the resonant frequency of the first oscillation mode, a frequency difference between the resonant frequencies of both oscillation modes being used for compensating for the effect of temperature on the frequency of the signal produced by the time base.Type: GrantFiled: August 29, 2003Date of Patent: February 22, 2005Assignee: ETA SA Fabriques D'EbauchesInventors: Metin Giousouf, Heinz Kück, Rainer Platz
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Patent number: 6848304Abstract: A six degree-of-freedom micro-machined multi-sensor that provides 3-axes of acceleration sensing, and 3-axes of angular rate sensing, in a single multi-sensor device. The six degree-of-freedom multi-sensor device includes a first multi-sensor substructure providing 2-axes of acceleration sensing and 1-axis of angular rate sensing, and a second multi-sensor substructure providing a third axis of acceleration sensing, and second and third axes of angular rate sensing. The first and second multi-sensor substructures are implemented on respective substrates within the six degree-of-freedom multi-sensor device.Type: GrantFiled: June 17, 2003Date of Patent: February 1, 2005Assignee: Analog Devices, Inc.Inventor: John A. Geen
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Patent number: 6845665Abstract: A micro-machined multi-sensor that provides 2-axes of acceleration sensing and 1-axis of angular rate sensing. The multi-sensor includes a rigid accelerometer frame, a first proof mass, and a second proof mass. The substrate has two associated acceleration axes in the plane of the substrate, and one associated rotation axis perpendicular to the acceleration axes. The proof masses have a common vibration axis, which is perpendicular to the rotation axis. The multi-sensor further includes a drive electrode structure for causing the proof masses to vibrate in antiphase, a first pair of acceleration sense electrode structures disposed along one of the acceleration axes, and a second pair of acceleration sense electrode structures disposed along the other acceleration axis.Type: GrantFiled: June 16, 2003Date of Patent: January 25, 2005Assignee: Analog Devices, Inc.Inventor: John A. Geen
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Patent number: 6843126Abstract: A triaxial sensor substrate is adapted for use in measuring the acceleration and angular rate of a moving body along three orthogonal axes. The triaxial sensor substrate includes three individual sensors that are arranged in the plane of the substrate at an angle of 120 degrees with respect to one another. Each sensor is formed from two accelerometers having their sensing axes canted at an angle with respect to the plane of the substrate and further being directed in opposite directions. The rate sensing axes thus lie along three orthogonal axes. In order to reduce or eliminate angular acceleration sensitivity, a two substrate configuration may be used. Each substrate includes three accelerometers that are arranged in the plane of the substrate at an angle of 120 degrees with respect to one another. The sensing axes of the accelerometers of the first substrate are canted at an angle with respect to the plane of the first substrate toward the central portion thereof so that they lie along three skewed axes.Type: GrantFiled: August 29, 2002Date of Patent: January 18, 2005Assignee: Honeywell International Inc.Inventor: Rand H. Hulsing, II
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Patent number: 6837107Abstract: A micro-machined multi-sensor that provides 1-axis of acceleration sensing and 2-axes of angular rate sensing. The multi-sensor includes a plurality of accelerometers, each including a mass anchored to and suspended over a substrate by a plurality of flexures. Each accelerometer further includes acceleration sense electrode structures disposed along lateral and longitudinal axes of the respective mass. The multi-sensor includes a fork member coupling the masses to allow relative antiphase movement, and to resist in phase movement, of the masses, and a drive electrode structure for rotationally vibrating the masses in antiphase. The multi-sensor provides electrically independent acceleration sense signals along the lateral and longitudinal axes of the respective masses, which are added and/or subtracted to obtain 1-axis of acceleration sensing and 2-axes of angular rate sensing.Type: GrantFiled: June 16, 2003Date of Patent: January 4, 2005Assignee: Analog Devices, Inc.Inventor: John A. Geen
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Publication number: 20040231419Abstract: An oscillation type of micro gyro sensor equipped with two vibrators is provided. The gyro sensor has a monitoring electrode, a signal processor, and a driving electrode attached to both the vibrators. The monitoring electrode monitors a vibration of only one of the two vibrators to output signal indicative of the monitored vibration. The signal processor drives the two vibrators in mutually opposite phases, by using the signal from said monitoring electrode. The driving electrode drives both the vibrators on the basis of the two driving signals.Type: ApplicationFiled: March 25, 2004Publication date: November 25, 2004Inventor: Hirofumi Higuchi
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Publication number: 20040211257Abstract: A micro-machined multi-sensor that provides 1-axis of acceleration sensing and 2-axes of angular rate sensing. The multi-sensor includes a plurality of accelerometers, each including a mass anchored to and suspended over a substrate by a plurality of flexures. Each accelerometer further includes acceleration sense electrode structures disposed along lateral and longitudinal axes of the respective mass. The multi-sensor includes a fork member coupling the masses to allow relative antiphase movement, and to resist in phase movement, of the masses, and a drive electrode structure for rotationally vibrating the masses in antiphase. The multi-sensor provides electrically independent acceleration sense signals along the lateral and longitudinal axes of the respective masses, which are added and/or subtracted to obtain 1-axis of acceleration sensing and 2-axes of angular rate sensing.Type: ApplicationFiled: June 16, 2003Publication date: October 28, 2004Applicant: ANALOG DEVICES, INC.Inventor: John A. Geen
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Publication number: 20040211256Abstract: A micro-machined multi-sensor that provides 2-axes of acceleration sensing and 1-axis of angular rate sensing. The multi-sensor includes a rigid accelerometer frame, a first proof mass, and a second proof mass. The substrate has two associated acceleration axes in the plane of the substrate, and one associated rotation axis perpendicular to the acceleration axes. The proof masses have a common vibration axis, which is perpendicular to the rotation axis. The multi-sensor further includes a drive electrode structure for causing the proof masses to vibrate in antiphase, a first pair of acceleration sense electrode structures disposed along one of the acceleration axes, and a second pair of acceleration sense electrode structures disposed along the other acceleration axis.Type: ApplicationFiled: June 16, 2003Publication date: October 28, 2004Applicant: ANALOG DEVICES, INC.Inventor: John A. Geen
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Patent number: 6789423Abstract: The present invention provides a micro inertia sensor and a method of manufacturing the same, the micro inertia sensor includes a lower glass substrate; a lower silicon including a first border, a first fixed point and a side movement sensing structure; an upper silicon including a second border, a second fixed point being connected to a via hole, in which a metal wiring is formed, on an upper side, and an sensing electrode, which correspond to the first border, the first fixed point and the side movement sensing structure; a bonded layer by a eutectic bonding between the upper silicon and the lower silicon; and a upper glass substrate, being positioned on an upper portion of the upper silicon, for providing the via hole on which an electric conduction wiring is formed, thereby aiming at the miniaturization of the product and the simplification of the process.Type: GrantFiled: December 27, 2002Date of Patent: September 14, 2004Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Seung Do An, Kyoung Soo Kim, Ji Man Cho
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Patent number: 6777857Abstract: Disclosed are coriolis force driven piezoelectric gyroscope systems which each comprise two substantially orthogonally oriented elements projecting from a mass. Each substantially orthogonally oriented element has a pair of electrodes present thereupon, wherein the electrodes in a pair thereof are oriented substantially parallel to one another. In use rotation about an axis oriented perpendicular to a plane formed by two substantially orthogonally oriented elements while an extension inducing driving voltage is applied across a pair of electrodes on one thereof. An output voltage, which is related to the rotation rate, is sensed across the pair of electrodes on the other substantially orthogonally oriented element.Type: GrantFiled: June 3, 2002Date of Patent: August 17, 2004Assignee: Board of Regents of the University of NebraskaInventor: Jiashi Yang
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Patent number: 6766689Abstract: The gyroscope is formed by a driving system including a driving mass having an open concave shape; an accelerometer including a sensing mass and comprising mobile sensing electrodes; a linkage connecting the driving mass to the sensing mass. The sensing mass is surrounded on three sides by the driving mass and has a peripheral portion not facing the sensing mass. The mobile sensing electrodes extend integral with the sensing mass from the peripheral portion not facing the driving mass and are interleaved with fixed sensing electrodes. Thereby, there are no passing electrical connections extending below the sensing mass. Moreover the linkage includes springs placed equidistant from the center of gravity of the accelerometer, and the gyroscope is anchored to the substrate with anchoring springs placed equidistant from the center of gravity of the assembly formed by the driving system and by the accelerometer.Type: GrantFiled: April 23, 2002Date of Patent: July 27, 2004Assignee: STMicroelectronics S.r.l.Inventors: Guido Spinola Durante, Sarah Zerbini, Simone Gardella
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Publication number: 20040134278Abstract: A two axis gyroscope including a planar vibratory resonator (5) having a ring or hoop-like structure, carrier mode drive means (22) for causing the resonator (5) to vibrate in a cos n&thgr; vibration mode, carrier mode pick-off means (23) for sensing movement of the resonator (5), X-axis response mode pick-off means (25; 27) for detecting movement of the resonator in response to rotation about the x-axis and y-axis; x-axis and y-axis response mode drive means (24; 26) for nulling said motions and support means (9) for flexibly supporting the resonator (5) and for allowing the resonator to vibrate relative to the support means (9) in response to the drive means (22) and to applied rotation; wherein the support (9) means comprises only L legs, where, when L is even: L=2N/K, and where, when L is odd: L=N/K, where K is an integer, L>2 and N is the carrier mode order.Type: ApplicationFiled: October 16, 2003Publication date: July 15, 2004Inventors: Christopher P Fell, Rebecka Eley, Colin H J Fox, Stewart McWilliam
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Publication number: 20040135466Abstract: A vibrator has a frame portion having a planar frame shape, an in-frame fixed portion which is fixed to a base portion and located in the inner space surrounded by the inner periphery of the frame portion, and a driving electrode comprising a first driving electrode disposed so as to confront the outer peripheral portion of the vibrator, and a second driving electrode which is equipped to the in-frame fixed portion so as to confront the inner peripheral portion of the frame portion, and the back-side portion of the in-frame fixed portion and the inner peripheral portion of the frame portion confronting the back-side portion are designed in an unevenly-shaped portion.Type: ApplicationFiled: November 24, 2003Publication date: July 15, 2004Inventor: Hirofumi Higuchi
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Patent number: 6752017Abstract: A yaw-rate sensor is proposed having a first and a second Coriolis element (100, 200) which are arranged side-by-side above a surface (1) of a substrate. The Coriolis elements (100, 200) are induced to oscillate parallel to a first axis. Due to a Coriolis force, the Coriolis elements (100, 200) are deflected in a second axis which is perpendicular to the first axis. The first and second Coriolis elements (100, 200) are coupled by a spring (52) which is designed to be yielding in the first and in the second axis. Thus, the frequencies of the oscillations in the two axes are developed differently for the in-phase and antiphase oscillation.Type: GrantFiled: March 19, 2003Date of Patent: June 22, 2004Assignee: Robert Bosch GmbHInventors: Rainer Willig, Andreas Thomae, Burkhard Kuhlmann, Joerg Hauer, Udo Martin Gomez, Siegbert Goetz, Christian Doering, Michael Fehrenbach, Wolfram Bauer, Udo Bischof, Reinhard Neul, Karsten Funk, Markus Lutz, Gerhard Wucher, Jochen Franz
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Patent number: 6742390Abstract: An angular velocity sensor includes four mass members which are connected by retaining beams, and the retaining beams are fixed to a substrate at node portions which correspond to nodes of the retaining beams when the mass members vibrate such that two adjacent mass members are in opposite phases. The mass members vibrate in an X-axis direction while the overall center of gravity is maintained at an approximately constant position. Two mass members disposed at the central region move in a Y-axis direction in accordance with an angular velocity about a Z axis, and the angular velocity is detected on the basis of the displacements thereof. The mass members vibrate in a stable vibrational state and dimensional errors or other problems, are compensated for by their shapes that are symmetric to each other in the Y-axis direction. Accordingly, the detection accuracy and reliability of the sensor are improved.Type: GrantFiled: January 10, 2003Date of Patent: June 1, 2004Assignee: Murata Manufacturing Co., Ltd.Inventors: Yoichi Mochida, Yoshihiro Konaka
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Patent number: 6725719Abstract: MEMS-Integrated IMUs are possible based on a common substrate that provides a common oscillatory drive for the operation of the gyroscopes and accelerometers. The common substrate becomes the stable member utilized in conventional IMUs. The advantages of the embodiments are smallest size, flexibility in how IMUs are configured, reduced electronics and a single package. MEMS integration also reduces uncertainties due to separately developed instruments based on different fabrication processes, materials, assembly and alignment.Type: GrantFiled: April 17, 2003Date of Patent: April 27, 2004Assignee: Milli Sensor Systems and Actuators, Inc.Inventor: Donato Cardarelli
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Patent number: 6722197Abstract: A suspended, coupled micromachined structure including two proof masses and multiple support arms configured to suspend the masses above a substrate and a coupling spring element having two ends. Each end of the coupling spring element may be attached to a proof mass at a point between the proof masses. The frequency response characteristics of the proof masses may be improved.Type: GrantFiled: June 19, 2001Date of Patent: April 20, 2004Assignee: Honeywell International Inc.Inventors: Gary R. Knowles, Mark W. Weber
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Patent number: 6715353Abstract: A microelectromechanical (MEMS) gyroscope has one or more proof masses mechanically coupled to a substrate by springs. A motor force drives the proof masses at their resonant frequency in one direction, 180 degrees out of phase with each other in the case of a dual proof mass gyroscope. Sense electrodes sense motion of the proof masses in response to a Coriolis force. The motion caused by the Coriolis force is perpendicular to the motion caused by the motor force. An AC pump voltage at twice the motor frequency is applied to the sense electrodes to provide parametric amplification of the Coriolis force. The AC pump voltage alters the mechanical and electrical gain of the gyroscope.Type: GrantFiled: April 25, 2002Date of Patent: April 6, 2004Assignee: Honeywell International, Inc.Inventor: Burgess R. Johnson
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Publication number: 20040045354Abstract: The invention relates to a micromechanical inertial sensor that comprises three component planes, namely a bottom part (12), a center part (11) and a cover part (13). The center part (11) is a silicon wafer in which a cardan-type structure (14) with two oscillating elements (15, 16) is formed. A plate (17, 18) is formed in the silicon wafer which can be pivoted about a rotational axis lying in the wafer plane. Metallized portions or conductive layers (19, 20, 21, 22) form an exciter unit and set the cardan-type structure oscillating. The inventive sensor further comprises a device for detecting the displacement of the plate (17, 18). Said structures represent a sensor module with a rotational rate sensor and at least one acceleration sensor that are produced by means of the same method.Type: ApplicationFiled: May 30, 2003Publication date: March 11, 2004Inventors: Konrad Lentner, Stefan Sassen, Josef Schalk
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Patent number: 6701786Abstract: The present invention provides an apparatus and method for measuring the angular rotation of a moving body. The apparatus comprises an upper sensor layer, a lower handle layer substantially parallel to the sensor layer, at least one dither frame formed of the upper sensor layer, the frame having a dither axis disposed substantially parallel to the upper sensor layer and the lower handle layer. The apparatus further comprises a first accelerometer formed of the upper sensor layer and having a first force sensing axis perpendicular to the dither axis for producing a first output signal indicative of the acceleration of the moving body along the first force sensing axis, the first accelerometer having a proof mass and at least one flexure connecting the proof mass to the dither frame such that the proof mass can be electrically rotated perpendicular to the dither axis.Type: GrantFiled: April 29, 2002Date of Patent: March 9, 2004Assignee: L-3 Communications CorporationInventor: Rand H. Hulsing, II
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Publication number: 20040035204Abstract: An integrated gyroscope, including an acceleration sensor formed by: a driving assembly; a sensitive mass extending in at least one first and second directions and being moved by the driving assembly in the first direction; and by a capacitive sensing electrode, facing the sensitive mass. The acceleration sensor has an rotation axis parallel to the second direction, and the sensitive mass is sensitive to forces acting in a third direction perpendicular to the other directions. The capacitive sensing electrode is formed by a conductive material region extending underneath the sensitive mass and spaced therefrom by an air gap.Type: ApplicationFiled: May 21, 2003Publication date: February 26, 2004Applicant: STMicroelectronics S.r.l.Inventors: Guido Spinola Durante, Sarah Zerbini, Angelo Merassi
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Patent number: 6662657Abstract: Performance-enhancing, reduced-area metalization adhesion areas in force-sensing transducers are described.Type: GrantFiled: June 25, 2002Date of Patent: December 16, 2003Assignee: Honeywell International, Inc.Inventors: Rand H. Hulsing, II, Randy Sprague
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Publication number: 20030217609Abstract: A vibrator that produces bending vibration with both ends unsupported is mounted on one principal surface of a mounting board, and a driving-and-detecting circuit component is also mounted to cross over an antinode center line of bending vibration of the mounting board due to resonance. The original self-resonance frequency of bending vibration of the mounting board itself is lower than the frequency of bending vibration of the vibrator. The modified self-resonance frequency of bending vibration of the mounting board when the vibrator and the driving-and-detecting circuit component are mounted thereon is higher than the original self-resonance frequency, and does not coincide with the frequency of bending vibration of the vibrator.Type: ApplicationFiled: March 25, 2003Publication date: November 27, 2003Inventors: Katsumi Fujimoto, Keiichi Okano, Masato Koike, Hironari Yamamoto
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Patent number: 6651500Abstract: An integrated rate and accelerometer sensor includes two counter vibrating tuned accelerometers formed in a single substantially planar silicon body to form the sensing element. The two vibrating accelerometers are interleaved in a manner that places their respective centers of mass in the same line parallel to the direction of the vibration and has the centers of percussion of the two (pendulum) proof masses coincident. A phase insensitive quadrature nulling method is utilized for each of the two vibrating accelerometers. The sensor structure utilizes Pyrex for the top and bottom covers. Metalized electrodes, feedthrus and contact pads are also utilized for the sensing element, instead of interlayer wire bonds.Type: GrantFiled: October 3, 2001Date of Patent: November 25, 2003Assignee: Litton Systems, Inc.Inventors: Robert E. Stewart, Stanley F. Wyse
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Patent number: 6626039Abstract: An oscillatory gyroscope is described with decoupled drive and sense oscillators and reduced cross-axis sensitivity. The gyroscope is fabricated using a plasma micromachining process on standard silicon wafers. The electrical isolation of the drive and sense functions of the gyroscope, contained within the same micromechanical element, reduce cross-coupling while obtaining high inertial mass and high sensitivity.Type: GrantFiled: September 13, 2000Date of Patent: September 30, 2003Assignee: MilliSensor Systems and Actuators, Inc.Inventors: Scott G. Adams, James Groves, Donato Cardarelli, Raymond Carroll, Charles R. Dauwalter
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Patent number: 6619123Abstract: A micromachined shock sensor has a substrate with a surface on which are formed an array of acceleration sensing units. Each sensing unit has a mount fixed to the substrate, a cantilever beam extending from the mount, and a proof mass fixed to the cantilever beam and supported above the substrate to permit translation of the proof mass and bending of the cantilever beam in a plane parallel to the substrate surface. Sensing electrodes are formed on the substrate on opposite sides of the proof mass such that displacement of the proof mass in response to acceleration brings the proof mass into contact with one or the other of the electrodes at a sufficient acceleration level, effectively closing a switch and providing an electrical output signal that can be detected. The multiple acceleration sensing units are formed to make contact at different levels of acceleration, allowing the shock sensor to allow measurements over a range of accelerations.Type: GrantFiled: June 4, 2001Date of Patent: September 16, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Shamus P. McNamara
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Publication number: 20030167842Abstract: By injecting noise into drive electronics, the start time of the MEMS gyroscope may be improved. A noise source is used to provide bandwidth limited white noise with a bandwidth centered substantially at the tuning fork frequency of at least one proof mass.Type: ApplicationFiled: March 7, 2002Publication date: September 11, 2003Applicant: Honeywell International Inc.Inventor: William P. Platt
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Patent number: 6595054Abstract: A digital angular rate and acceleration sensor is constructed with force-sensitive resonators positioned longitudinally on one or both sides of the neutral bending plane of a cantilevered structure. The cantilevered structure has an inertial proof mass at its free end with a periodic velocity applied sideways to the bending plane. Rotation about the longitudinal axis, which produces periodic Coriolis acceleration, as well as inertial acceleration applied perpendicular to the bending plane, generate tensile and compressive forces on the resonators thereby altering the resonant frequencies that are thus a measure of angular rate of rotation and acceleration.Type: GrantFiled: May 14, 2001Date of Patent: July 22, 2003Assignee: Paroscientific, Inc.Inventors: Jerome M. Paros, Theo P. Schaad
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Patent number: 6595056Abstract: A micromachined silicon tuned accelerometer gyro is formed out of silicon wafers, by micromachining. The top and bottom cover which include driver, forcer, tuning and guard ring elements mounted therein are micromachined in arrays on silicon-on-insulator (SOI) wafers. The center (driver and sensing) element between the top and bottom is micromachined in an array of four inch diameter silicon wafers. The driver and sensing structure is a tuned pendulum attached by flexure joints to a vibrating structure which is in then suspended by a parallelogram dither suspension. The pendulum is tuned by adjusting the magnitude of a d.c. signal to match the natural frequency of the pendulum to the natural frequency of the vibrating structure. The dither suspension flexures of the vibrating structure is uniquely defined and easily machined but yet provides a dither suspension that restrains the vibrating structure within its vibrating plane with no harmonic distortion.Type: GrantFiled: February 7, 2001Date of Patent: July 22, 2003Assignee: Litton Systems, IncInventor: Robert E. Stewart
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Patent number: 6584845Abstract: The inertial sensor of the present invention utilizes a proof mass suspended from spring structures forming a nearly degenerate resonant structure into which a perturbation is introduced, causing a split in frequency of the two modes so that the mode shape become uniquely defined, and to the first order, remains orthogonal. The resonator is provided with a mass or inertia tensor with off-diagonal elements. These off-diagonal elements are large enough to change the mode shape of the two nearly degenerate modes from the original coordinate frame. The spring tensor is then provided with a compensating off-diagonal element, such that the mode shape is again defined in the original coordinate frame. The compensating off-diagonal element in the spring tensor is provided by a biasing voltage that softens certain elements in the spring tensor. Acceleration disturbs the compensation and the mode shape again changes from the original coordinate frame.Type: GrantFiled: February 10, 2000Date of Patent: July 1, 2003Assignee: California Institute of TechnologyInventors: Roman C. Gutierrez, Tony K. Tang
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Patent number: 6575032Abstract: A suspension for a gyroscopic float assembly in a floating gyroscope system comprises a pair of flexures that each have an outer rim and a plurality of flexure beams extending from the outer rim. A plurality of flexure tabs extend outward from outer perimeter portions of the rims for mounting the flexure assembly to a pair of end caps. A plurality of strain relief passages formed in the rims is arranged to provide relief from thermally induced stresses. A plurality of angular stops formed in inner perimeter portions of the rims is arranged to constrain the flexure against rotation about a selected axis.Type: GrantFiled: July 27, 2001Date of Patent: June 10, 2003Assignee: Litton Systems, Inc.Inventors: Richard Anderson, Devadas Dorai-Raj
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Patent number: 6557415Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.Type: GrantFiled: July 19, 2002Date of Patent: May 6, 2003Assignee: Northrop Grumman CorporationInventors: Robert E. Stewart, Stanley F. Wyse
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Patent number: 6557414Abstract: A sensor device has a sensing layer and an auxiliary layer for supporting the sensing layer, the two layers being superposed on each other in a laminar form. The sensing layer has a vibratory body displaceable in a direction parallel to a junction surface between the two layers. The auxiliary layer is affixed to the sensing layer and a recess or through-hole of a larger area than that of the vibratory body is formed in the auxiliary layer at a part thereof confronting the vibratory body.Type: GrantFiled: October 5, 2001Date of Patent: May 6, 2003Assignee: Hitachi, Ltd.Inventors: Kohei Sakurai, Masahiro Komachiya, Masahiro Matsumoto, Seikou Suzuki
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Publication number: 20030056590Abstract: A vibration gyro has a vibrator composed of three tines (first, second, and third tines) which are aligned in a single line at prescribed intervals in one direction on a base and extend in a direction perpendicular to an aligning direction. A central second tine and an adjacent first tine on a left are driven by oscillator. Further, Coriolis force generated on the second tine and the third tine on a right is detected by a detector. In this vibration gyro, the dimensions of the parts are determined so as to cause the third tine to substantially stand still when the first and second tines are driven by the oscillator.Type: ApplicationFiled: September 6, 2002Publication date: March 27, 2003Inventors: Tohru Yanagisawa, Izumi Yamamoto
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Publication number: 20030037614Abstract: A method and system for measuring angular speed of an object uses a micromechanical filter apparatus and allows Q-multiplication in both drive and sense modes. The invention takes advantage of the constant amplitude region of a filter spectrum within a passband of the filter apparatus to sense with a constant scaling factor that is independent of frequency variations with the passband. Thus, the system has much less sensitivity to drive mode resonance frequency shifts due to temperature variations, fabrication non-idealities and aging. The system senses angular rate or speed at resonance, which results in a great improvement over conventional gyroscopes operated off-resonance.Type: ApplicationFiled: January 23, 2002Publication date: February 27, 2003Inventors: Clark T.-C. Nguyen, Mustafa U. Demirci